(1) Field of the Invention
The present invention generally appertains to improvements in fire hydrants and more particularly relates to a new and novel guard arrangement for preventing unauthorized turning of the operating stem for the valve control rod and, in the instance of hydrants with weather guards, protecting such weather guards from unauthorized operation.
(2) State of the Art
Most urban areas have a fire fighting hydrant system and the unauthorized opening of one fire hydrant can cause a sometimes very critical loss of adequate water pressure in the system. This has long been recognized and, consequently, many attempts have been made to combat vandalism and prevent unauthorized turning of the valve control rod. In such instances, the aim has been to control and permit only authorized turning of the operating stem which projects above the bonnet or hood on top of the stand pipe.
For example, in U.S. Pat. Nos. 3,840,041 and 3,916,939, magnetic type arrangements of rather complicated construction have been disclosed. Such arrangements require major modification of the hydrant and, of course, suffer from the deficiency that loss of magnitism of the magnitized parts would render such mechanisms useless.
Another type of arrangement is shown in U.S. Pat. No. 4,033,372 wherein a very elaborate device is provided to protect the hydrant stem and includes a hood or dome that fits over the entire top of the hydrant including the stem. The protective dome is held in place by legs bolted to the hydrant. Such bolts could be easily removed, thereby permitting the entire device to be removed from the hydrant by one not authorized to do so. Further, the arrangement consists of many specially made parts and suffers from the disadvantage that the hood or dome which fits over the bonnet of the hydrant must be made in various sizes since there are numerous bonnet sizes presently in use.
Another prior device is shown in U.S. Pat. No. 2,118,233 wherein a protective collar encircles the stem with the collar being fixed to the bonnet by legs that are attached to the bonnet fixing bolts of the hydrant. The attaching legs are inadequate to hold the collar in place because the removal of one or more bolts would permit the complete removal of the device from the hydrant bonnet. Such removal could be easily carried out by an unauthorized person.
In U.S. Pat. No. 3,453,655, a device is shown wherein a collar is built around the hydrant stem. However, such collar will still permit unauthorized access by use of an ordinary type of wrench to the stem and the device involves a rather complicated method of modifying the hydrant stem so as to permit installation of a positive locking device.
As can be appreciated, the devices of the prior art, as exemplified by the forgoing patents, are very complicated and most expensive so that they really possess no practical value for installation on hydrants, regardless of the configurations or constructions of the hydrants, on a large scale basis. And, only if every hydrant in an urban area can be protected will the entire fire-fighting hydrant system be maintained in proper operation so that there will always be a sufficient water pressure in such system.